Refrigerating apparatus.



No. 894,285. I PATENTEA) JULY 28,1908.

' H. RASSBACH.

REFRIGERATING APPARATUS.

APPLICATION FILED SEPT.14, 1903.

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UNITED STATES PATENT OFFICE.

HERMANN RASSBACH, OF MILWAUKEE, WISCONSIN. ASSIGN 011 TO THE VILTERMANUFAC- TUBING COMPANY, OF MILWAUKEE, WISCOhSl'N, A CORPORATION OFWISCONSIN.

REFRIGERATING. APPARATUS.

Specification of Letters Patent.

Patented July 28, 1908.

Application filed September 14, 1903. Serial No. 173,031.

To a] Z whom it may concern: v Be it known that I, ,HERMANN RASSBACH, acitizen of the United States, residing at Milwaukee, in the countyofgMilwaukee and State of Wisconsin, have invented certain new anduseful Improvements in Refrigerating Apparatus, of which the followingis a specification, reference being had to the accompanying drawing,forming a part thereof. This invention relates to that class ofrefrigerating apparatus in which a volatile liquid is employed as therefrigerant to, absorb or abstract the heat of surrounding or adjacentbodies or substances, and the gas or .vapor resulting from theevaporation of the liquid is reliquefied, so that the same refrlgerantis used over and over again in a con,

tinuous cycle.

The main-objects of the invention are to automatically regulate thesupply of a cooling agent to a plurality of coils or chambers or to theseveral parts of a refrigerating system according to the varyingconditions and demands in such a system, and thus over- 5 come thedifiiculties heretofore eX erienced in supplying to each of the severaparts of the system the requisite quantity-of cooling agent for theefiective and economical operation thereof; to avoid the return ofliquefied 39 gas to the compressor or other condensing apparatus; toreturn to the refrigerating plates or coils or to the expansion chambersall of the cooling agent which is discharged therefrom in aliquid state,thereby utilizing 5 its full efficiency to avoid the care, trouble anduncertainty incident to the manual regulation of the supply of thecooling agent to the several parts of a refrigerating system; to utilizethe liquefied refrigerant condensed 40 by the operation of throwing offand liberating the finished ice from the freezing plates for immediateand effective work in active freezing coils; and generally to simplifyand improve the construction and operation of apparatus of this class.

The invention consists in certain novel features of construction and inthe peculiar arrangement and combinations of parts hereinafterparticularly described and summarized in the claims.

In the accompanying drawing like characters designate the same parts inboth figures. Figure 1 is a diagram and sectional view of apparatusembodying the invention and designed for use in the manufacture of ice;

and Fig. 2 is a perspective view of a part of the apparatus shown inFig. 1.

Referring to Fig. 1, showing refrigerating apparatus embodyingmyinvention, h designates a closed tank or reservoir, which may becalledan accumulator.

& designates one of a number of cooling coils or pipes, which for thepurpose of more readily liberating the ice formed thereon, are coveredon both sides by thin metal sheets j, held in close contact therewith bymetal straps or bars 9'' which support the several sections or parts ofeach coil and are bolted thereto over the edges of said sheets, as shownin Figs. 1 and 2. These sheets on the opposite side of each coil arealso connected and clamped to the coil by bolts at intervals betweensaid supporting straps or bars. As they do not or need not form watertight chambers for the coils and are not required to support the coils,they may be and are preferably made comparatively thin and light. Anydesired number of these coils covered as above stated are-arranged atsuitable intervals and parallel with each other in a steel or metal tankk, for holding the water to be frozen. The ends of the coils areconnected with horizontal headers or manifolds Z and m, theirconnections therewith being provided with stop cocks n and 0, for thesole purpose, as hereinafter explained, of shutting ofi any of saidcoils from said headers. header Zis located below and connected with thelower part of the accumulator h in such relation thereto and to thecoils that when the cooks n and 0 are opened, liquid will flow from theaccumulator by gravity alone into and simultaneously fill or partiallyfill all the coils to the same level. The header m is located above theheader Z. and is connected with the accumulator at any convenient andsuitable point above the bottom thereof.

The l The top or upper part of the accornulator h v accumulator orreturnconduit for the gas'areconnected in this pipe, which is provided at aconvenient point between the coil a and the suitable material, andinclosing an air space along the sides and bottom of the tank. This sace is divided midway between and paralle with the coils by the timberswhich support the tank or otherwise, into ducts or passages :10, andthese ducts communicate through ports or openings controlled by valvesy, with an air duct 2 extending along one side of the tank and connectedwith a source of hot or warm air.

Each of the coils t is connected at its upper outlet end with a header2, which is in turn connectedby a pipe 3 with the discharge pipe 8between the compressor q and the condenser t. The connection of eachcoil with the header 2 is provided with a valve 4.

The several spacesbetween the sheet metal covered coils in the tank areconnected with each other at the bottom by a header 5 and branch pipes6, provided with valves 7, by means of which connections a uniform waterlevel: is maintained in the several parts of the tan To determine andmaintain a certain depth of water in the tank 7c it is provided with anoverflow pipe 8. The tank is supplied with water from a header 9,provided at convenient intervals with valves and hose connections 10. q

Branch pi es 11 provided with valves '12, lead into the lower parts ofthe sections of the freezing tank from one or more compressed air supplymains 13.

My improved apparatus, constructed and arranged for making ice ashereinbefore described, operates as follows: It is well known to thosefamiliar with the art to which my invention pertains, that liquidanhydrous ammonia boils, or is converted into a gaseous state at atemperature of about t Fahrenheit below zero, and under a pressure ofabout fifteen pounds per square inch above that of the atmosphere. It isalso well understood that for converting a liquid into a gas or vapor,heat is required. If therefore, the accumulator h is partially filled,as shown in Fig. 1, with liquid anhydrous ammonia, at the temperatureand under the pressure above mentioned, this liquid will flow by gravitythrough the header Z into the coils i, filling them all to the level ofthe liquid contained in the accumulator. The liquid ammoma coming incontact with the metal pipe QOIlS which have a temperature correspondingwith that of the Water in the freezing tank, this temperaturebeing muchhigher thanthe boiling point of the ammonia, will boil or be convertedinto vapor or gas, ab-

sorbing the heat for its evaporation from the coils and surroundingwater. The ammonia steam or gas thus produced entraining with it more orless of the liquid ammonia, will escape from the coils through themanifold m, into the accumulator, where the liquid will be precipitated,while the gas separating vfrom the li uid passes by the pipe 1), throughthe forecoo er 1, to the com ressor g, to be recompressed and returned trough the condenser t and cooling'coil a into the accumulator. Theliquid refrigerant thus returned from the coils and precipitated in theaccumulator under the same pressure and hence at the same temperature asthe gas escaping therefrom, being available for effective work, flowsagain into the active freezing coils.

The heat of the water in tank is transferred to the liquid ammonia inthe coils i, converts the same into steam or gas. It follows that thetemperature of the water Will thus be reduced until it reaches thefreezing oint and congeals'on the plates the ice ecoming graduallythicker while the process of evaporation and circulation of therefrigerant in the coils is continued. This process of evaporation ismade continuous by the supply through the pipe 8 to the accumulator fromthe compressor of an amount of liquid ammonia equal to that escapingfrom the accumulator in the form of gas to' the compressor. The liquidammonia returning from the compressor through the condenser to. theaccumulator, is of a much higher temperature and under much greaterpressure than are maintained in the evaporating and cooling coils of theapparatus. If the liquid refrigerant were liberated from the highpressure under which it is delivered from the condenser, its sensibleheat at the, high tem erature corresponding to that pressure Wou d beconsumed at once in converting a part of such liquid into gas, and thatpart would be lost for effective refrigeration in the freezing coils. Toprevent this loss it is necessary to deprive the liquid refrigerant ofits excess of sensible heat and thus destroy its @718 viva, before it isadmitted into the accumulator and before itis relieved from its highpressure.

The warm liquid ammonia coming from the compressor, before it enters theaccumulator through the regulating valve 12 to repeat its circuitthrough the freezing coils, is passed v uid ammonia to the accumulatorthrough this single valve, the proper conditions of pressure can bereadily mamtained in the accumulator and cooling coils, while the liquidrefrigerant will be supplied and distributed automatically by gravityand by gravity alone, from the accumulator through the header 1 to theseveral freezing coils accordin to the conditions and requirements inthe di erent parts of the system. As freezing progresses and the icebecomes thicker on the metal sheets covering the coils, therebyretarding the transmission of heat from the water to the coils, theevaporation of the refrigerant Within the coils becomes less active; butsince the temperature of the refri erant depends upon the pressure'underwhic it is he d, the same or even a greater congealing eflect will beexerted upon the surrounding medium when the refrigerant is in a densecondition than when it is in a state of ebullition within the coilsunder the same pressure.

While the process of freezing is goin on there is always more or lessevaporation 0 the refrigerant in the coils and the column of denseliquid in the accumulator and its connections with the lower ends of thecoils being heavier than the column of rarefied liquic rising to thesame level'within the coils, a constant circulation of the refrigerantthrough the coils is maintained, and since the I liquid refrigerant isheld under an invariable volume of vapor or pressure and at aninvariable temperaturein the coils and accumulator, it exerts a moreenergetic cooling effect than a corresponding as with its comparativelysmall amount of specific heat.

In the practical operation of this system, about the same quantity ofice is finished and taken out of the freezing tank every day, so thatWhile the finished product is being removed from. certain parts, theprocess of freezing is at different stages of progress in other parts ofthe tank, resulting in a more or less active evaporation and circulationof the refrigerant in such parts. Nevertheless, the aggregateevaporation in the entire system remains ractically constant, andtherefore, the supp y of li uid refri erant to all the active freezing00' s should e uniformly maintained.

It follows that the means and method of forecooling the liquidrefrigerant while it is held under high pressure to the temperature ofthe refrigerant contained in the accumulator before it is admitted intothe accumulator, the regulation or control of the supply of suchrefrigerant to'the accumulator by a single valve and the automaticdistribution and supply of the liquid refrigerant under low pressure 'tothe several active freezing coils, according to varyin conditions anddemands, by gravity an by gravity alone, are essential distinctivefeatures of the present invention. a

When the ice has attained the desired thickness, say 12 to 14 inches, incertain parts of the freezing tank, it is liberated by admitting gasunder-pressure through the valves 4 into the correspondin coils 4,,after the cocks at and 0 have b'eenc osed to shut such coils off fromthe accumulator. The coils and thin metal sheets 3' covering them, arethus warmed by the gas, which is in turn cooled and liquefied. Insteadof returning this liquefied gas to the suction side of the compressor,and thereby obstructing its ac tion in connection with other arts of thesystem, it is discharged by sligi ftly opening the valves it intothemanifold Z, and thus utilized under the conditions of pressure andtemperature therein maintained, to supply the cooling coils which remainin operation.

To detach the ice cakes from the bottom and sides of the tank k to whichthey are also frozen, hot air is admitted to the adjoining passages 00from the supply duct 2 by opening the proper valves y. The parts of themetal tank to which the ice cakes adhere are thus warmed sufficiently torelease said cakes and permit their removal. As soon as, or even before,the ice cakes are removed, the process of freezing is resumed in thosesections or parts of the tank from which the cakes are taken, by simplyopening the cocks at and 0, after closing the valves 4 of thecorresponding' coils. While the cakes are being removed, an equivalentvolume of water is supplied to the tank from the forecooler r or a coldwater reservoir through the header 9 and hose attached to one or more ofthe valveslO.

During the process of freezing, the water in the several parts of thetank is continuously agitated by forcing compressed air into it near thebottom of the tank through the pipes 11. This prevents impurities whichare eliminated by the freezing process from adhering to the icecakes-and becoming embedded therein, and as a result, a crystal clearproduct is obtained from water which has not been subjected todistillation or filtration. To render this agitation uniform throughoutthe freezing tank, the water in the several sections or parts of thetank,

which are separated from each other by the formation of the ice, is keptat the same level by means of the connecting pipe 5 and its branches 6,which communicate with said sections orspaces midway between the coilswhere no ice is formed. Without these connections the water would assumedifferent 'levels in different parts of the tank, on account of theexpansion which takes place' .with the formation of the ice and itsvarying thickness at different stages of its formation. Any materialvariation in the water level in theseveral parts of the tank wouldprevent uniform agitation of the water through which the air dischargedinto it takes the, course of least resistance, and would result in lackof uniformity in the purity of the ice, since greater agitation wouldtake place in those in the apparatus herein shown and described may beutilized for other purposes than making ice, as for example, by omittingthe freezing tank in which the cooling coils are placed, said coilseither with or without the metal sheets 7' attached thereto, orevaporation chambers of any suitable form, may be used to cool thesurrounding air or other mediums or substances for cold storage rooms orother purposes, the effect of variations in the temperature of the airor other mediums or substances surrounding or adjacent to the coolingcoils upon the operation of the apparatus being the same as variationsin the temperature of water in contact with said coils in the productionof ice, as herein explained.

An suitable apparatus for recondensing or re iquefying the gas after ithas been evaporated in the freezing or cooling coils orchambers andreturning the same in a liquid.

state to the accumulator may be used.

Instead of warming the metal tank is to detach the ice therefrom bymeans of hot air, any other suitable means may be provided in the spacebetween the tank and its insulation jacket or casing. In short, variouschanges in details of construction and arrangement of parts may be madeto adapt the apparatus to the various purposes to which it is applicablewithout materially affecting its operation and without departing fromthe principle and intended scope of my.

invention.

When in the claims a freezing coil or chamber is mentioned it is to beunderstood as including one or more freezing coils or chambers.

It is to be clearly understood that a distinctively novel feature of theinvention is cooling the refrigerant while held under the high pressureof the system to the temperature of the refrigerant in the accumulatorheld under the low pressure of the system, so as to bring therefrigerant into condition to flow by gravity from the accumulator toand through the freezing coil or chamber.

I claim:

1. In a refrigerating apparatus, an accumulator, a freezing coil orchamber having a gravity inlet connection from the accumulator and anoutlet connection therewith, a supply connection from a liquefyingapparatus for the refrigerant to the accumulator, means in the supplyline for releasing the refrigerant from high to low pressure, and meanswhere by the refrigerant while held under the high pressure of thesystem may be given the temperature of the refri erant in theaccumulator held under the ow pressure of the system.

2. In refrigerating apparatus the. combination with liq uefyingapparatus, of an accumulator, which has a gas outlet connection with thesuction side of the liquefying apparatus and a supply connection withthe discharge side of said apparatus, a coollng coil or chamber having agravity inlet connection from said accumulator and an outlet connectiontherewith, said su ply connection being provided with a valve forreleasing the refrigerant from high to low pressureand arranged to be exosed to the gas on its return to the lique ing apparatus from thecooling coil or chamber to give to the refrigerant while held under thehigh pressure of the system the temperature of the refrigerant in theaccumulator under the low pressure of the system.

3. In' refrigerating apparatus the combination of an accumulator havingasu ply connection provided with a valve for re easing the refrigerantfrom high to low pressure, a gas outlet connection leading from theupper part of the accumulator, a plurality of cooling coils'or chambersarranged at substantially the same level with one another, a headerhaving a gravity-inlet connection with said accumulator; the lowerportions of the coils being connected with said header and the-uppernections with t e accumulator, and means whereby the refrigerant whileunder the high pressure of the system may be iven the temperature of therefrigerant held at the low pressure of the system within theaccumulator.

4. In refrigerating apparatus the combination with liquefying apparatus,of an accumulator having a gas outlet connection leading from the u perpart thereof to the suction side of the iquefying apparatus and arefrigerant supply connection with the discharge sideof said apparatusleading through and exposed to the gas in the upperpart of theaccumulator and provided with a controlling valve after its passagethrough the same, and one or more cooling coils or chambers each havinga gravity inlet connection with said accumulator and an outletconnection therewith above its inlet connection, substantially asescribed.

5. In refrigerating apparatus the combination with a compressor, of anaccumulator having gas return and refrigerant supply connections withsaid compressor, means in the supply connection for releasing thereortions having outlet consystem, the header having a gravity suplpfrigerant from high to low pressure, means whereby the refrigerant Whileheld under the high pressure of the system may be given the temperatureof the refrigerant in the accumulator under the low pressure of the yconnection with the accumulator; a plura lty of freezing coils orchambers the lower parts of which are connected with said header and theupper parts of which have outlet connections with the accumulator, stococks in the connections of said coils or c ambers with said header andwith the accumulator, direct valvecontrolled connections between theseveral coils or chambers and the compressor, 15 and a freezing tankcontaining said coils or chambers, substantially as described.

In witness whereof, I hereto affix my signature in presence of twowitnesses.

HERMANN RASSBACH.

Witnesses:

H. H. BERGMANN, GEORGE M. EMMERIoH.

